混凝土介电特性与强度的相关性研究

Research on the Correlation between Dielectric Properties and Strength of Cement Concrete

为了探究微波无损检测技术应用于水泥净浆与混凝土抗压强度检测的可能性,分别对水灰比为0.4、0.5、0.6的水泥净浆和混凝土试件进行了介电特性实验和抗压强度试验,探究两者之间的相关性。研究表明:介电常数的实部和虚部都与混凝土的强度和龄期存在一定的相关性。通过回归拟合分析,建立了不同龄期时,介电常数实部、虚部与抗压强度间的相关关系模型。在相同的龄期下,介电常数与抗压强度呈正向线性关系,7 d龄期下的介电常数相关系数实部为0.7962,虚部为0.7903;14 d龄期下的实部为0.8692,虚部为0.8753;28 d龄期下的实部为0.9247,虚部为0.9278,两者之间的相关关系随时间变化越来越好。

In order to explore the possibility of the application of microwave nondestructive testing technology in compressive strength test of cement paste and concrete,the dielectric properties and compressive strength tests are conducted on cement paste and concrete specimens with water cement ratios of 0.4,0.5 and 0.6 respectively to explore the correlation between them.The research shows that the real part and imaginary part of complex dielectric constant has certain relevance with the strength and age of concrete.The correlation model between the real and imaginary parts of the dielectric constant and the compressive strength at different ages is established through regression fitting analysis.Under the same age,the dielectric constant has a positive linear relationship with the compressive strength.The correlation coefficient of the real part and the imaginary part of the dielectric constant at 7 d age is 0.7962 and 0.7903 respectively,0.8692 and 0.8753 at 14 d age respectively,and 0.9247 and 0.9278 at 28 d age respectively,shows that the correlation is getting better and better with the increase of age.